These can supply hot water to a whole house, with the burner lighting automatically whenever any hot tap is turned on. The water temperature is thermostatically controlled and can be set to a safe 55°C.
Some models are computer controlled and turn the heat up or down according to the amount of hot water being drawn off. Some even have remote control panels so you can set the temperature near the point of use.
There are no standing heat losses with these systems, as no hot water is stored, but research by the Building Research Association of New Zealand (BRANZ) has shown that houses with instant hot water use more hot water than those with other forms of water heating.
Continuous flow systems have a limit on flow rate and a shower may lose flow if other hot taps are turned on in the house so it’s important that you select the correct size of water heater for your needs. These systems are likely to be the most expensive of the gas options to buy and install, but the cheapest to run. As with all gas options, the larger your family, the more cost-efficient they become.
The main attractions: endless hot water, saves space.
The main drawbacks: People with a continuous flow unit relish the unlimited supply of hot water so much their hot water usage increases.
If you want to use gas, and don't have a street connection, a cylinder-swap LPG system could work well.
- In most cases a budget price would be between $3000 - $3800 incl GST